• Differences in 14C Age Between Stratigraphically Associated Charcoal and Marine Shell from the Archaic Period Site of Kilometer 4, Southern Peru: Old Wood or Old Water?

      Kennett, Douglas J.; Ingram, B. Lynn; Southon, John R.; Wise, Karen (Department of Geosciences, The University of Arizona, 2002-01-01)
      Consistently large differences occur in the calibrated 14C ages of stratigraphically associated shell and charcoal samples from Kilometer 4, an Archaic Period archaeological site located on the extreme south coast of Peru. A series of nine shell and charcoal samples were collected from a Late Archaic Period (approximately 6000-4000 BP) sector of the site. After calibration, the intercepts of the charcoal dates were approximately 100-750 years older than the paired shell samples. Due to the hyper-arid conditions in this region that promote long-term preservation of organic material, we argue that the older charcoal dates are best explained by people using old wood for fuel during the Middle Holocene. Given this "old wood" problem, marine shell may actually be preferable to wood charcoal for dating archaeological sites in coastal desert environments as in southern Peru and Northern Chile.
    • Late Quaternary Chronology and Stratigraphy of Twelve Sites on Kaua'i

      Burney, David A. (Department of Geosciences, The University of Arizona, 2002-01-01)
      Twelve new sites on Kaua'i provide an island-wide view of late Quaternary (near time) environments on the oldest of the major Hawaiian Islands. Radiocarbon-dated lithologies are compared for estuarine sites on windward and leeward coasts, interior peat bogs ranging from 169 to 1220 m in elevation, prehistoric fishponds, and a sinkhole paleolake in the Maha'ulepu cave system. Terrestrial sedimentation begins in many coastal sites about 6000 cal BP, as sea level approached modern levels. Prehuman sedimentation rates were quite low in all these sites, generally <2 mm/yr, although coastal sites in the late Holocene were subject to major episodic sediment influx from extreme events, including tsunamis, hurricanes, and floods. Interior sites are generally older, having accumulated humic clay and peat layers at least since the late Pleistocene. Since the arrival of humans less than two millennia ago, sedimentation rates have increased in some coastal sites, and further local increases (as much as two orders of magnitude) have occurred since European arrival. Evidence from sites containing fossils of extinct terrestrial snails is consistent with the hypothesis that human-caused extinctions have proceeded in three phases, corresponding to losses (generally the largest species) occurring soon after the arrival of the first humans, followed by a second wave of extinction in late prehistoric times, and a third after European colonization. Dating of sediments from fishponds constructed or enhanced by prehistoric Polynesians suggests that this early form of aquaculture was initiated on Kaua'i by about 830 +/50 BP. The most elaborate example of fishpond construction in the Hawaiian Islands, the Alekoko or Menehune fishpond on Kaua) i's southeast coast, was probably undertaken by 580 +/30 BP.